Quick-change mechanism for a tie bar

ABSTRACT

A casting machine is disclosed having a quick-change tie bar mechanism. This mechanism includes an actuator having a rod coupled to a first bearing member and a body coupled to a second bearing member. The first and second bearing members are configured to reciprocally move in opposite directions in response to extension and retraction of the rod relative to the body. The bearing members have a first configuration for engaging a nut threaded on a tie bar to fix the tie bar in relation to a platen through which the tie bar extends. The first and second bearing members also have a second configuration for releasing the tie bar to permit removal through the platen so that a part may be accessed for removal and/or replacement. In another embodiment, a number of platens are included as are a number of tie bars configured to guide movement of one of the platens relative to another.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication Serial No. 60/092,859 filed Jul. 15, 1998.

Commonly owned U.S. Provisional Patent Application No. 60/092,859, filedJul. 15, 1998 of which the benefit is claimed herein is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to casting and molding systems, and moreparticularly, but not exclusively, relates to a mechanism to moreefficiently interchange parts of a casting or molding machine.

One common type of casting machine includes four tie bars that guidevertical movement of one platen relative to another. U.S. Pat. No.4,716,952 to Hegel et al. and U.S. Pat. No. 5,263,531 to Drury et al.are cited as additional sources of background information concerningsuch devices and their operation. To change casting parts for this typeof machine, usually at least one of the tie bars needs to be removed.The process of disassembling a tie bar from the machine to change partsis generally very time-intensive and costly. Thus, there is a need toprovide a quicker way to remove casting machine tie bars.

Some attempts to improve the removal of tie bars have included devicesof the type described in U.S. Pat. No. 5,192,557 to Hirata et al. andU.S. Pat. No. 5,542,465 to Wolniak. Unfortunately, these devices areexceedingly complex, including multiple actuators and a large number ofmoving parts that take up an excessive amount of space. Also, devices ofthis type typically do not provide for the independent adjustment of anut threaded on an end portion of the tie bar to accommodate changes intie bar tension while the tie bar is assembled in the machine. Thus,there remains a need for a better tie bar clamping or holding device.Preferably, such a device would facilitate turning a nut threaded on thetie bar to adjust tic bar tension.

SUMMARY OF THE INVENTION

One form of the present invention includes a unique casting or moldingmachine having a releasable tie bar clamping or holding mechanism.Alternatively or additionally, another form of the present invention isa unique technique to selectively hold and remove a tie bar.

In a further form, a mechanism has a pair of bearing members and anactuator. The actuator is coupled to each of the bearing members and isoperable to reciprocally move the bearing members in oppositedirections. Accordingly, the mechanism may be utilized to move thebearing members towards each other to facilitate holding or clamping ofa structure and to move the bearing members away from each other torelease the structure. This mechanism may be arranged to align with anopening of a platen through which a tie bar is passed, such that thebearing members are positioned on opposite sides of the tie barextending through the opening. A nut may be threaded on the tie bar tobear against the bearing members and correspondingly hold the tie bar infixed relation to the platen.

Accordingly, it is one object of the present invention to provide aunique casting or molding machine having a releasable clamping orholding apparatus.

It is another object of the present invention to provide a uniquetechnique for holding and selectively removing a tie bar.

It is still another object to provide a quick-change mechanism for a tiebar. Further objects, features, forms, aspects, benefits, and advantagesof the present invention shall become apparent from the description anddrawings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial, diagrammatic side view of a casting system of thepresent invention.

FIG. 2 is a partial, exploded perspective view of a mechanism of thesystem of FIG.

FIG. 3 is a perspective view of the mechanism of FIG. 2 shown in aclosed, holding configuration.

FIG. 4 is a partial, sectional view taken along section line 4—4 of FIG.3.

FIG. 5 is a perspective view of the mechanism of FIG. 2 shown in anopen, releasing configuration.

FIG. 6 is a partial, sectional view taken along section line 6—6 of FIG.5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates.

FIG. 1 depicts die casting system 10 including quick-change mechanism 20and casting machine 40 (partially shown). Mechanism 20 is operablycoupled to machine 40 for releasably holding a quick-change tie bar 42 aof machine 40. Machine 40 also includes three tie bars 42 b. Only one oftie bars 42 b is shown in FIG. 1, with the other two each being directlybehind a corresponding one of tie bars 42 a, 42 b depicted. Preferablytie bars 42 a, 42 b are each positioned to generally coincide with acorner of an imaginary rectangle or square in a standard manner like thetie bar and platen arrangement shown in U.S. Pat. No. 5,542,465 toWolnaik. Machine 40 includes moveable platen 44 a and base platen 44 bthat are in engagement with tie bars 42 a, 42 b. Tie bars 42 a, 42 beach have a generally circular cross section, and each tie bar 42 a, 42b passes through an opening through platen 44 a and an opening throughplaten 44 b. Tie bars 42 a, 42 b are each rigidly fixed to platen 44 bwhen performing a casting operation with machine 40. In contrast, platen44 a is arranged to reciprocally travel along tie bars 42 a, 42 brelative to platen 44 b during casting operations. Tie bars 42 a, 42 bguide and align platen 44 a as it travels. Hydraulic cylinder 80(partially shown) is coupled to platen 44 a to control movement alongtie bars 42 a, 42 b in a standard manner.

Tie bar 42 b has a threaded end arranged for engagement by acorresponding nut 43. Tie bar 42 b is maintained in a fixed relationshipwith platen 44 b for casting operations by threading nut 43 on tie bar42 b and tightening nut 43 so that it bears against platen 44 b. Nut 43is sized to have an outside diameter that is larger than the maximumoutside diameter D1 of each tie bar 42 a, 42 b in order to bear againstplaten 44 b. Quick-change tie bar 42 a is also coupled to platen 44 b;however, lower end portion 60 of tie bar 42 a is threaded and engaged bynut 45. Nut 45 may be tightened to selectively bear against mechanism 20as will be more fully described in connection with FIGS. 3-6hereinafter. End portion 60 has diameter D2 which is less than maximumdiameter D1 of bars 42 a, 42 b (D2<D1). Nut 45 is sized so that it maybe withdrawn through an aperture having a diameter no greater than D1when nut 45 is threaded on end portion 60. Correspondingly, the maximumdimension of nut 45 transverse to tie bar 42 a when threaded thereon issmaller than D1. Lock nut 47 is threaded on end portion 60 of tie bar 42a adjacent nut 45 to provide a locking action. Preferably, lock nut 47also has a maximum dimension transverse to tie bar 42 a that is alsosmaller than D1. Likewise, lock nuts may be used to secure each nut 43in place. Nuts 43, 45 may be turned while in a bearing relationship withplaten 44 b to adjust tension of tie bars 42 a, 42 b during performanceof casting operations with machine 40.

Platens 44 a, 44 b are typically rectangular in shape; however, in otherembodiments, platens 44 a, 44 b may be shaped and arranged differentlyas would occur to those skilled in the art. Preferably, the ends of tiebars 42 a, 42 b not shown in FIG. 1 are secured to a plate, frame, orother member as is known in the art. Also, casting machine 40 mayinclude more or fewer tie bars 42 a, 42 b and/or other geometricarrangements of bars 42 a, 42 b as would occur to those skilled in theart.

Machine 40 is preferably oriented to provide for generally verticaltravel of platen 44 a along axis VV. Alternatively, machine 40 may beoriented for generally horizontal travel of platen 44 a or travel ofplaten 44 a along another direction as would occur to those skilled inthe art. Various other parts 82, 84 are attached to platens 44 a, 44 b,respectively. Parts 82, 84 may be die casting elements, molds, or othermachine constituents. It is usually desirable to remove one or more ofparts 82, 84 from time-to-time for cleaning and reinstallation, or toexchange with other parts; however, one of tie bars 42 a, 42 b typicallyneeds to be displaced to facilitate removal and replacement of parts 82,84.

The selective fixation and displacement of tie bar 42 a is facilitatedby mechanism 20. Mechanism 20 is mounted to machine 40 by screws (notshown) to releasably hold or clamp tie bar 42 a in fixed relation toplaten 44 b. Referring additionally to FIG. 2, a partial exploded viewof mechanism 20 is provided. FIG. 2 shows mechanism 20 in an invertedorientation relative to FIG. 1 and without other portions of system 10to enhance clarity. Mechanism 20 includes base 22 in the form ofmounting plate 24 with hole 24 a sized to clear the outside diameter oftie bar 42 a with nuts 45, 47 threaded thereon. Guide rails 23 areattached to plate 24 by screws 25. Rails 23 are generally straight andare spaced apart from one another a generally constant distance. Rails23 each have a cross section taken along axis AA that generally has aninverted L-shape with an inwardly protruding flange 23 a. Rails 23 arepositioned opposite each other about hole 24 a. Nonetheless, in otherembodiments, rails 23 may be arranged or shaped differently as wouldoccur to those skilled in the art.

Mechanism 20 also includes blocks 26 a, 26 b configured to slidablyengage rails 23. Block 26 a, 26 b are assembled to slide between rails23 along axis AA. Each block 26 a, 26 b has a pair of opposing railengaging portions with a generally C-shaped cross section taken alongaxis AA to engage flange 23 a of a corresponding one of rails 23.Preferably, blocks 26 a, 26 b and rails 23 are sized so that blocks donot make substantial contact with plate 24 when engaged to flanges 23 aof rails 23. Blocks 26 a, 26 b each define a corresponding taperedcollar portion 50 a, 50 b that collectively define tapered collar 50.Collar portions 50 a, 50 b define passage 51 therebetween that isaligned and intersects hole 24 a.

The size and shape of collar 50 and passage 51 vary with any change inspacing between collar portion 50 a and collar portion 50 b as blocks 26a, 26 b correspondingly move relative to each other along rails 23.Preferably, the taper of collar portion 50 a, 50 b is contoured tocompliment a contacting face of nut 45. It is also preferred that collarportions 50 a, 50 b each be Contoured to define a semicircular endsurface opposite one another.

Mechanism 20 also includes opposing bridle rails 27 attached to block 26b by screws 28. Bridle rails 27 are each positioned to travel along anouter side of a corresponding one of rails 23. Bridle rails 27 areconnected to end plates 28 a, 28 b at opposing ends by screws 29. Endplate 28 a extends over block 26 a to couple to each bridle rail 27 andabuts block 26 b. End plate 28 b abuts block 26 b and includes two slotsto receive rails 23 therein. Once assembled, block 26 b, bridle rails27, and end plates 28 a, 28 b travel together along axis AA.

Stops 30 a, 30 b are attached to plate 24 by screws 31 opposite oneanother between rails 23. Stops 10 a, 30 b are arranged to limit travelof blocks 26 a, 26 b along rails 23 and contain blocks 26 a, 26 bbetween rails 23. While, stops 30 a, 30 b are shown generally spanningthe entire distance between rails 23, in other embodiments, stops 30 a,30 b may only occupy a portion of this distance or may otherwise beconfigured to limit travel of blocks 26 a, 26 b. In one alternativeembodiment, the ends of rails 23 are shaped to limit the travel ofblocks 26 a, 26 b, and stops 30 a, 30 b are not utilized. Preferably,rails 23, 27; plates 24, 28 a, 28 b; blocks 26 a, 26 b; and stops 30 a,30 b are made from steel; however, alternative materials as would occurto those skilled in the art are also contemplated.

Referring to FIGS. 1, 3, 5; mechanism 20 is shown with double-actinghydraulic cylinder actuator 32. As in the case of FIG. 2, FIGS. 3 and 5are inverted and only show selected portions of system 10 to enhanceclarity. Actuator 32 includes a threaded plunger stem or rod 33 threadedinto threaded hole 34 defined by end plate 28 a. Actuator 32 alsoincludes body 35 fixedly connected to plate 26 a. Referring specificallyto FIG. 1, actuator 32 is coupled to control 70 by hydraulic lines 72 a,72 b. Control 70 includes a standard hydraulic pump, and anelectromechanical interface of a standard type to control actuator 32 inthe usual maimer for a double-acting hydraulic cylinder.Correspondingly, rod 33 is selectively extended and retracted relativeto body 35 along axis AA in response to activation by control 70. Inother embodiments, a different type of actuator may be used such as apneumatic device or a device that electromagnetically extends and/orretracts a stem or rod, to name only a few. Control 70 and lines 72 a,72 b could likewise be adapted to accommodate such alternative actuatortypes.

Referring again to FIGS. 3 and 5, block 26 a is arranged to serve as abearing member 21 a. Collectively, block 26 b, bridle rails 27, and endplates 28 a, 28 b comprises another form of a bearing member designatedby reference numeral 21 b. End plate 28 a of bearing member 21 bincludes bridge portion 31 spanning across block 26 a of bearing member21 a generally transverse to axis AA. Bearing members 21 a, 21 b move inopposite directions along rails 23 and between stops 30 a, 30 b inresponse to extension or retraction of rod 33 relative to body 35 ofactuator 32. Rod 33 may be repositioned relative to body 35 to changethe distance separating collar portion 50 a and collar portion 50 badjacent hole 24 a. Correspondingly, different positions of rod 33relative to body 35 provide different configurations of bearing members21 a, 21 b. Of particular interest are the closed or holdingconfiguration of bearing members 21 a, 21 b shown in FIGS. 3 and 4 andthe open or releasing configuration of bearing members shown in FIGS. 5and 6.

Referring to FIGS. 3 and 4, selected aspects of the holdingconfiguration are shown. FIG. 4 is a partial, cross-sectional view takenalong section line 4—4 of FIG. 3 and further includes portions of platen44 b, tie bar 42 a, and nuts 45, 47. For the holding configuration, rod33 is retracted into body 35 of actuator 32 so that body 35 and endplate 28 a are in close proximity to one another. The relationship ofmechanism 20 to platen 44 b and tie bar 42 a is further detailed in FIG.4. Tie bar 42 a has a centerline axis BB that is preferably generallyperpendicular to axis AA of mechanism 20. Platen 44 b defines opening 41therethrough. Opening 41 is aligned with hole 24 a through plate 24 andpassage 51 through collar 50. Correspondingly, tie bar 42 a passesthrough opening 41, hole 24 a, and passage 51. As previously described,tie bar 42 a necks down with a progressively smaller diameter attransition region 62 as end portion 60 is approached along axis BB.

Nut 45 includes a sloped contacting face 45 a arranged to engage taperedcollar 50 defined by collar portions 50 a, 50 b of bearing members 21 a,21 b, respectively. The obliquely sloped or ramped surfaces of collar 50and nut 45 relative to axis BB of tie bar 42 a and axis AA assist in theproper alignment and seating of tie bar 42 a and nut 45 relative tomechanism 20. Lock nut 47 is also shown tightened against nut 45.

Nut 45 is sized with a maximum dimension less than or equal to diameterD1 of the upper portion of tie bar 42 a, such that nut 45 may passthrough opening 41 and hole 24 a while threaded on end portion 60.However, for the holding configuration, collar 50 and passage 51 aresized with a minimum dimension to prevent passage of nut 45 therethroughas shown in FIG. 4. While in the preferred embodiment, collar portion 50a, 50 b are arranged to come together to define a generally circularcollar 50 about passage 51. In other embodiments, collar 50 and portions50 a, 50 b may be shaped and sized differently to selectively preventthe passage of nut 45 through opening 41 and hole 24 a. For example,collar portions 50 a, 50 b could each have generally planar end surfacesthat are spaced apart from each other such that only a portion ofopposing sides of face 45 a may be engaged thereby. In other examples,collar portions 50 a, 50 b may each be shaped with one or moreprotruding prongs to contact nut 45 while allowing passage of endportion therebetween, or otherwise shaped as would occur to thoseskilled in the art. Likewise, in alternative embodiments, blocks 26 a,26 b may be differently shaped and arranged as would occur to thoseskilled in he art. Nut 47 may be sized to pass through opening 41 andhole 24 a, or may be sized larger or smaller than nut 45. If nut 47 islarger, then it may need to be removed to withdraw tie bar 42 a troughopening 41 or hole 24 a. In still other embodiments, nut 45 may be sizedin a manner requiring removal before withdrawal of tie bar 42 a throughopening 41 or hole 24 a.

For the holding configuration of FIG. 4, bearing members 21 a, 21 b arearranged to define working space 64 about nuts 45, 47 to facilitateaccess for tightening or loosening nuts 45, 47 while bearing members 21a, 21 b are in the holding configuration. This operation may includeapplying a conventional tool (not shown) to turn nut 45 or nut 47. Byaccommodating such an operation, tension of tie bar 42 a may becorrespondingly adjusted. Rod 33 is in a retracted position in body 35when in the holding configuration, with an end portion of rod 33remaining threaded in hole 34 defined by plate 28 a to maintain a fixedconnection between rod 33 and bearing member 21 b. In contrast, body 35is fixed to bearing member 21 a. A separation distance along axis AAbetween block 26 a of bearing member 21 a and stop 30 a is about thesame as the distance separating end plate 28 b of bearing member 21 band stop 30 b along axis AA, These separation distances correspond tothe amount of distance bearing members 21 a, 21 b may travel along rails23 between stops 30 a, 30 b.

Mechanism 20 selectively moves between the holding configuration shownin FIGS. 3 and 4 to the releasing configuration shown in FIGS. 5 and 6through activation of actuator 32. In response to appropriate operatoractivation of control 70, rod 33 moves along axis AA from the retractedposition for the holding configuration to an extended position for thereleasing configuration. As rod 33 extends from body 35, it pushesagainst end plate 28 a. Because of the fixed connection of block 26 b toend plate 28 a, bridle rails 27, and end plate 28 b, they move togetheras bearing member 21 b travels towards stop 30 b. Extension of rod 33also causes body 35 of actuator 32 and bearing member 21 a to move alongaxis AA towards stop 30 a. When transitioningfrom the holdingconfiguration to the releasing configuration, bearing members 21 a, 21 bmove in opposite directions along rails 23 away from one another andaway from opening 41 and hole 24 a. Correspondingly, the distanceseparating collar portions 50 a, 50 b increases along axis AA when goingfrom the holding configuration to the releasing configuration. Duringtransition, bearing members may move simultaneously or may each morealternatively. For example, if a greater resistance to the travel of onerelative to the other is encountered, it may temporarily halt travel ofthat one while the other continues until the greater resistance isovercome or reduced. Preferably, the maximum extension of rod 3 frombody 15 is slightly greater than that needed to move bearing member 21 ainto abutment with stop 30 a and bearing member 21 b into abutment withstop 30 b (see FIGS. 5 and 6). For this preference, even if movement ofone of the bearing members 21 a, 21 balong rails 23 is halted byresistance before it encounters its corresponding stop 30 a, 30 b,bearing contact between the other bearing member 21 a, 21 b and itscorresponding stop 30 a, 30 b is likely to overcome such resistanceuntil both bearing members 21 a, 21 b contact their respective stops 30a, 30 b.

As members 21 a, 21 b move between the holding and releasingconfigurations they travel past one another. Specifically, bridgeportion 31 of end plate 28 a, passes adjacent block 26 a during suchtransitions. This arrangement of members 21 a, 21 b may be characterizedas a “stacked” relationship. For the embodiment depicted, the stackingis generally vertically oriented; however, it may alternatively behorizontal or otherwise oriented in accordance with the alignment ofmechanism 20.

An extended position of rod 33 of actuator 32 is shown in FIGS. 5 and 6with bearing members 21 a, 21 b abutting stops 30 a, 30 b, respectively.Correspondingly, collar portions 50 a, 50 b are separated by a greaterdistance than for the holding configuration and passage 51 has increasedin size.

Passage 51 and collar portions 50 a, 50 b are arranged in the releasingconfiguration to permit withdrawal of tie bar 42 a along axis BB throughhole 24 a and opening 41. Preferably, nuts 45, 47 are sized relative topassage 51, hole 24 a, and opening 41 so that they may be withdrawnwhile still threaded on end portion 60 of tie bar 42 a. Nut 45 and/ornut 47 may be loosened prior to attaining the releasing configuration.In other embodiments, nuts 45 or 47 may be removed before or afterwithdrawal of tie bar 42 a through hole 24 a and opening 41.

Once released, withdrawal of tie bar 42 a may be performed with anotherhydraulic cylinder or small crane (not shown) to displace tie bar 42 a aselected distance or remove it from machine 40 entirely; therebyfacilitating removal and/or replacement of one or more of parts 82, 84mounted on the platens 44 a, 44 b, respectively. After removal of any ofparts 82, 84 and any subsequent reinstallation or exchange, tie bar 42 ais re-inserted through opening 41, hole 24 a, and passage 51. Actuator32 is activated to retract rod 33 reciprocally, and correspondingly movebearing members 21 a, 21 b. As rod 33 retracts, bearing members 21 a, 21b move in opposite directions towards opening 41, hole 24 a, and eachother to re-establish the holding configuration. With re-establishmentof the holding configuration, nut 45 may be configured to lock upagainst collar portions 50 a, 50 b of corresponding blocks 26 a, 26 b,keeping tie bar 42 a fixed relative to platen 44 b. Tension of tie bar42 a may be re-adjusted during casting operations with system 10 afterthe holding configuration is re-established by turning nut 45 to tightenor loosen it, as needed. Notably, maintenance of proper tension for alltie bars 42 a, 42 b is usually desired to prevent binding of platen 44 aas it travels along tie bars ⁴²a, 42 b in the directions indicated bythe arrows shown in FIG. 1.

In one nonlimiting example, mechanism 20 is utilized on an 850 toncasting machine. For this example, diameter D1 of tie bar 42 a is about9.5 inches which necks down to a diameter D2 of about 7.5 inches at endportion 60. The taper of collar 50 for this example is about 10°relative to axis AA. In other embodiments, mechanism 20 may be utilizedwith differently sized casting or molding machines. Also, tie bar 42 aand collar 50 may be sized and shaped differently as would occur tothose skilled in the art.

Other examples of the present invention include a first casting machineplaten and a second casting machine platen arranged to move relative tothe first platen to perform a casting operation. A number of tie barsare arranged to guide movement of the second platen relative to thefirst platen during the casting operation, and at least one of these tiebars passes through an opening defined through the first platen and hasnut threaded thereon. A tie bar holding mechanism is coupled to thefirst platen and includes a first bearing member, a second bearingmember, and an actuator. The actuator includes a body and a rodselectively moveable relative to the body. The first bearing member iscoupled to the body to move therewith and the second bearing member iscoupled to the rod to move therewith. The rod has a first positionrelative to the body to correspondingly position both of the bearingmembers in a holding configuration to selectively bear against the nutthreaded on one of the tie bars. The rod has a second position relativeto the body to correspondingly position the first and second bearingmembers in a releasing configuration to permit withdrawal of one of thetie bars through the opening with the nut threaded thereon.

Another embodiment of the present invention includes a pair of generallystraight rails operable to be connected to a casting machine platenabout an opening through the platen. A pair of bearing members are alsoincluded that are arranged to slidably engage the rails. One of thebearing members has a first collar portion and another of the bearingmembers has a second collar portion. The collar portions are positionedopposite one another and between the rails, and define a passage toreceive the tie bar. An actuator precludes a body and a rod each coupledto a different one of the bearing members when engaged to the rails toprovide a mechanism. The rod is positioned between the rails and isselectively extendable and retractable relative to the body to move thebearing members in opposite directions when configured in thismechanism. The mechanism has a first position that orients the collarportions to selectively establish a bearing contact to hold the tie barin a fixed relation to the platen. The mechanism has a second rodposition that orients the collar portions to selectively withdraw thetie bar through the opening of the platen.

Still another embodiment of the present invention includes a platen anda number of tie bars for coupling to the platen with at least one of thetie bars passing through an opening defined through the platen. Alsoincluded is a releasable tie bar holding mechanism coupled to theplaten. The mechanism includes a pair of bearing members and an actuatorincluding a body and a stem selectively moveable relative to the body.The bearing members move apart from one another and each move away fromthe opening in response to movement of the stem relative to the body ina first direction. The bearing members move closer to one another andeach move closer to the opening in response to movement of the stemrelative to the body in a second direction generally opposite the firstdirection. The stem has a first position relative to the body toposition the bearing members in a tie bar fixing configuration. Also,the stem has a second position relative to the body to position thebearing members in a tie bar releasing configuration.

A further embodiment of the present invention includes a casting machinehaving a number of platens and means for releasably clamping a tie barin relation to one of the platens to selectively bear against a nutthreaded on the tie bar with a pair of bearing members selctivelypositioned relative to an opening of the platen through which the tiebar passes. The bearing members are slidably coupled to the platen by apair of generally straight rails. The releasable clamping means includesa hydraulic cylinder actuator having a body coupled to one of thebearing members to move therewith and a rod coupled to another of thebearing members to move therewith. The rod is selectively moveablerelative to the body along an axis located generally midway between andapproximately parallel to the rails to reciprocally move the bearingmembers.

Other embodiments include providing or operating a casting machine thathas a platen defining a number of openings and a corresponding number oftie bars that each extends through a respective one of the openings. Adesignated one of the tie bars is selectively held in place relative tothe platen with a mechanism. This mechanism includes a pair of bearingmembers in bearing contact with a nut threaded on the designated tie barand an actuator. The actuator has a body fixed to one of the members anda selectively moveable rod coupled to another of the members. The rod isextended relative to the body to move the bearing members away from theopening in generally opposite directions. The designated tie bar iswithdrawn along with the nut threaded thereon through the respectiveopening of the platen. A part for the casting machine is changed afterthis withdrawal. The designated one of the tie bars is inserted throughthe opening of the platen after the part is changed. The rod of theactuator is retracted relative to the body to move the bearing memberstowards the opening to engage the nut threaded on the designated tie barand the nut is turned to adjust tension of the designated tie bar.

Further, all patents, patent applications, and publications cited in thepresent application are hereby incorporated by reference as if each werespecifically and individually indicated to be incorporated by referenceand set forth in its entirety herein.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the game is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges, equivalents, and modifications that come within the spirit ofthe invention as defined by the following claims are desired to beprotected.

What is claimed is:
 1. An apparatus, comprising: a first casting machineplaten; a second casting machine platen arranged to move relative tosaid first platen to perform a casting operation; a number of tie barsarranged to guide movement of said second platen relative to said firstplaten during said casting operation, at least one of said tie barspassing through an opening defined through said first platen and havinga nut threaded thereon; a mechanism coupled to said first platen, saidmechanism including a first bearing member, a second bearing member, andan actuator aid actuator including a body and a rod selectively moveablerelative to said body, said first bearing member being coupled to saidbody to move therewith and said second bearing member being coupled tosaid rod to move therewith; and wherein said rod has a first positionrelative to said body to correspondingly position both of said first andsecond bearing members in a first configuration to selectively bearagainst said nut threaded on said one of said tie bars, and said rod hasa second position relative to said body to correspondingly position saidfirst and second bearing members in a second configuration to permitwithdrawal of said one of said tie bars through said opening with saidnut threaded thereon.
 2. The apparatus of claim 1, wherein said one ofsaid tie bars has an end portion with said nut threaded thereon, andsaid end portion has a smaller diameter than another portion of said oneof said tie rods.
 3. The apparatus of claim 1, wherein said actuatorincludes a hydraulic cylinder and further comprising an operatoractivated control operably coupled to said cylinder.
 4. The apparatus ofclaim 1, wherein said actuator includes a double-acting hydrauliccylinder with said rod extending further from said body in said secondposition than said first position.
 5. The apparatus of claim 1, furthercomprising a pair of generally straight rails connected to said firstplaten, said first and second bearing members slidably engaging saidrails and wherein: said rod extends along an axis approximately parallelto said rails and said rod is positioned between said rails; said firstbearing member includes a first collar portion, said second bearingmember includes a second collar portion, and said first and secondcollar portions define a passage receiving a portion of said tie rodtherethrough when in said first configuration; and one of said first andsecond bearing members moves over another of said first and secondbearing members when changing from said first configuration to saidsecond configuration.
 6. An apparatus, comprising; a casting or moldingmachine including a tie bar with a nut threaded thereon and a platendefining an opening arranged to receive said tie bar therethrough; apair of rails arranged to connect to said platen about said opening; apair of bearing members each arranged to slidably engage said rails, oneof said bearing members defining a first collar portion and another ofsaid bearing members defining a second collar portion, said first andsecond collar portions being positioned opposite one another betweensaid rails and defining a passage aligned to receive said tie bartherethrough when said bearing members engage said rails; a hydrauliccylinder actuator including a body and a rod each arranged to couple toa different one of said bearing members when said rails are engaged bysaid bearing members to provide a quick-release mechanism with said rodbeing positioned between said rails and being selectively positionablerelative to said body to move said bearing members in oppositedirections when configured in said mechanism, said mechanism beingoperable when said tie bar extends through said opening and said passageto provide a first rod position that orients said first md second collarportions to selectively bear against said nut to hold said tie bar infixed relation to said platen and a second rod position that orientssaid first and second collar portions to selectively withdraw said tiebar through said opening; and wherein at least a portion of a first oneof said bearing members travels past at least a portion of a second oneof said bearing members in an opposite direction when changing said rodbetween said first and second positions.
 7. The apparatus of claim 6,wherein said portion of said first one of said bearing members includesa bridge portion crossing said portion of said second one of saidbearing members.
 8. The apparatus of claim 7, wherein said first one ofsaid bearing members is coupled to said rod and includes a pair ofbridle rail members connected to said bridge portion to move therewithand said rod is threaded into a threaded hole defined by said bridgeportion.
 9. The apparatus of claim 6, further comprising a pair of stopsat opposite ends of said rails to limit motion of said bearing member.10. The apparatus of claim 9, further comprising a plate configured forconnection to said platen, said rails being fixed to said plate, saidplate defining an aperture arranged for alignment with said openingthrough said platen when said plate is connected to said platen.
 11. Anapparatus, comprising: a platen; a number of tie bars arranged to coupleto said platen during performance of a casting operation, at least oneof said tie bars passing through an opening defined through said platen;a releasable tie bar holding mechanism coupled to said platen, saidmechanism including a pair of bearing members and an actuator includinga body and a rod selectively moveable relative to said body, saidbearing member moving apart from one another and each moving away fromsaid opening in response to movement of said rod relative to said bodyin a first direction, and said bearing members moving closer to oneanother and each moving closer to said opening in response to movementof said rod relative to said body in a second direction generallyopposite said first direction; and wherein said rod has a first positionrelative to said body to position said bearing members in a tie barholding configuration, and said rod has a second position relative tosaid body to position said bearing members in a tie bar releasingconfiguration.
 12. The apparatus of claim 11, further comprising a pairof generally straight rails connected to said first platen, said bearingmembers slidably engaging said rails.
 13. The apparatus of claim 12,wherein said rod extends along an axis located generally midway betweensaid rails and approximately parallel to said rails, said bearingmembers slidably moving along said rails in response to a change inposition of said rod relative to said body.
 14. The apparatus of claim11, wherein said one of said tie bars has an end portion with a firstnut threaded thereon, said end portion has a smaller diameter thananother portion of said one of said tie bars, said end portion and saidfirst nut are sized to pass through said opening with said first nutthreaded thereon and said bearing members engage said first nut to clampsaid one of said tie bars to said first platen when in said tie barholding configuration.
 15. The apparatus of claim 14, further comprisinga second nut threaded on said end portion to engage said first nut, saidfirst nut being arranged to adjust tension of said one of said tie barsand said second nut being arranged to lock said first nut in position.16. The apparatus of claim 11, wherein said first platen defines anumber of openings each correspondingly receiving a respective one ofsaid tie bars therethrough, said tie bars each having at least one of acorresponding number of nuts threaded thereon.
 17. The apparatus ofclaim 11, wherein said actuator is a double-acting hydraulic cylinder,and said rod extends from said body a greater distance for said secondposition than said first position.
 18. The apparatus of claim 11,wherein said bearing members each include a corresponding one of a pairof collar portions, said collar portions are positioned opposite oneanother, and said collar portions define a passage to receive a portionof said one of said tie bars therethrough and selectively bear against anut threaded on said one of said tie bars when in said tie bar holdingconfiguration.
 19. An apparatus, comprising: a casting machine includinga first platen, a second platen arranged to reciprocally move relativeto said first platen to perform a casting operation, and a number of tiebars arranged to guide movement of said second platen relative to saidfirst platen during said casting operation, one of said tie bars havinga nut threaded thereon and extending through an opening defined throughsaid first platen, said opening being sized to permit withdrawal of saidtie bar through said first platen with said nut threaded thereon, saidmachine further comprising: means for releasably clamping said one ofsaid tie bars in relation to said first platen by selectively bearingagainst said nut with a pair of bearing members controllablypositionable relative to said opening and being slidably coupled to saidfirst platen by a pair of generally straight rails, said means includinga hydraulic cylinder actuator, said actuator having a body coupled toone of said bearing members to move therewith and a rod coupled toanother of said bearing members to move therewith, said rod beingselectively moveable relative to said body along an axis locatedgenerally midway between and approximately parallel to said rails toreciprocally move said bearing members, said bearing members beingpositioned to prevent said nut threaded on said one of said tie barsfrom passing through said opening in correspondence with a firstposition of said rod relative to said body and said bearing membersbeing positioned to allow withdrawal of said one of said tie rodsthrough said first platen in correspondence with a second position ofsaid rod relative to said body.
 20. A method, comprising: operating acasting machine, the machine including a platen defining a number ofopenings and a corresponding number of tie bars, the tie bars eachextending through a respective one of the openings; holding a designatedone of the tie bars extending through the respective one of the openingswith a mechanism including a pair of bearing members in bearing contactwith a nut threaded on the designated one of the tie bars and ahydraulic cylinder including a body coupled to one of the members and aselectively moveable rod coupled to another of the members; extendingthe rod relative to the body to move the bearing members away from theopening in generally opposite directions; withdrawing the designated oneof the tie bars and the nut threaded thereon through the opening of theplaten after said extending; changing at least one part for the castingmachine after said withdrawing; inserting the designated one of the tiebars through the opening of the platen after said changing; retractingthe rod relative to the body to move the bearing members towards theopening; establishing a bearing contact between the nut threaded on thedesignated one of the tie bars and the bearing members; and turning thenut during the bearing contact with the bearing members to adjusttension of the designated one of the tie bars.
 21. The method of claim20, wherein said extending includes sliding the bearing members along apair of generally straight rails connected to the platen.
 22. The methodof claim 21, wherein at least a portion of one of the bearing membersmoves over at least a portion of another of the bearing members duringsaid sliding.
 23. The method of claim 20, wherein the bearing membersclose about a portion of the designated one of the tie bars in responseto said retracting.
 24. The method of claim 20, wherein said extendingincludes releasing the tie bar from said holding.